Manufacture of sulfuric acid.



U. WEDGE. MANUFACTURE OF SULFURIG AGID. APPLIUATION FILED SEPT. 18, 1909.

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MANUFACTURE OF SULFURIG ACID.

APPLIOATION FILED SEPT. 18, 1909.

Patented July 21, 1m

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UTLEY WEDGE, or ARDMOBCE, runusxmrama manuracrunnor sormro acm Specification of Letters, latent, Applioation filed September 18, 1909. Serialflo. 518,395..

Ratented July 21, 1 14.

To all whom it may concern:

Be it known that I, UTLEY' VVEDGE, a citizen of the United States, residing in Ardmore, Pennsylvania, have invented certain Improvements in the Manufacture of. Sulfuric Acid, of which the following is a specification.

The object of my invention is to facilitate the manufacture of sulfuric acid, especially that This object I attain in the manner hereinafter set forth, reference being had to the accompanying drawing, which represents, in diagrammatic form, apparatus constructed for the carrying out of my invention, Figure 1 being a side elevation of the apparatus, and Fig. 2 a plan view of the same.

In the manufacture of sulfuric acid from blast furnace gases much difliculty has been experienced because of the high temperature of the blast furnace gases, the large amount of steam created by moisture in the blast furnace charge, and the presence of excessive amounts of nitrogen or carbonic acid gas which, in addition to acting as diluents of the sulfurous acid gas, also serve to carry into the sulfuric acid process heat units out of proportion to the sulfuric acid" produced. It is desirable to utilize this heat in the Glover tower for the concentration of sulfuric acid, but, when this heat is so utilized the'gas leaves the Glover tower and enters the lead acid chambers either at an abnormally high temperature or carrying an excessive amount of steam. In the one case the high temperature causes destructive action upon the lead walls and tops of the chambers owing to excessive chemical action at such high temperature, and in the other case, the amount of steam entering the chambers is so excessive as to greatly dilute the sulfuric acid produced or interfere with the securing of proper chemical reaction, resulting in the consumption of excessive amounts of nitrate of soda or nitric acid. I find that these objections can be overcome and the production of the acid facilitated if the mixture of sulfurous and nitrous gases issuing from the Glover tower is caused to pass at relatively high speed through a series of chambers of small cross section and presenting a cooling surface which, in proportion to the cubic capacity of the chamber, is much greater than that of the ordinary lead chamber. By reason of the rapid radiation of heat due to the produced from blast furnace gases.

large area of exposed surface of these chamhers, 111]111'10118 action of the gases upon the head, because of their high temperature, is minimized, and, especially if the passage for the flow of the gases is of a tortuous character, the intimate admixture of the gases and the steam during such flow will result in the formation ofthe sulfuric acid more rapidly than in the ordinary chamber of large capaclty, the surplus steam being absorbed or incorporated in the sulfuric acid which is produced, thereby, in great measure, reliev;

, ing any subsequent chamber or chambers of g the series from the performance of this duty.

In the drawing, 1 represents the blast fur- I nace or other generator of sulfurous gas, 2

Lthe Glover tower into which the gases are introduced from the blast furnace and from which they pass to a manifold 3, having 1 branches leading to the primary members of a plurality of rows of lead towers 4, the gases being withdrawn from the last members of the rows by means of suitable exhaust fans 5 and driven by the latter into the usual lead chambers 6 for the completion of the process. The towers 4 have very limited cross sectional area in proportion to their height, being about 10 feet square and feethigh, and they are composed of aprons of lead supported by any suitable external framework, the towers being connected alternately at top and bottom, as shown in Fig. 1, so that the gases and steam in passing through the towers are caused to follow a tortuous course and are subjected to constant agitation and admixture. during their flow. Any desired number of these towers may be employed according to the capacity of the apparatus. In one apparatus avhich Ihave constructed, where the temperature of the blast furnace gases when they leave the furnace is from 1100 F. to 1800 F. and the temperature of the gases after they leave the Glover tower is from 240 F. to 250 F., I have employed 7 2 towers, arranged in eight rows of nine towers to the row with the idea of soreducing the temperature of the gases in their passage that they will issue from the final towers at a temperature of about 190 F at which temperature they enter the ordinary lead chambers (3. The effect of using this bank of towers as compared with the use of an ordinary lead chamber will be understood when it is borne in mind that a lead cnam-.

ber 50 feet square and feet high," while and having a cubic capacity of 187,500 feet presents a surface area of only 16,500 feet, or

area of 208,800 feet, or more than four foot of surface for each tenths of a square I cubic foot of capacity, andthe same proportions holdggood irrespective of the numher of towers of this size which may be employed. This is due, in some measure, to the very small percentage of the total surface area of each tower which rests upon the ground and is therefore unavailable as a cooling surface although the chambers 4 may be disposed horizontally instead of vertically, if they are so supported that the air can gain access to their under sides. I

I do not desire to limit my invention to a tower or chamber of such size or disposition that it presents'a surface area as high in proportion to cubic space as that above indicated, as good results can be obtained with a chamber which is so proportioned or dis-' posed that the surface area presented is as low as three tenths of a square foot to each cubic foot of-chamber space.

The steam combined with the gases is condensed by the-lowering of the temperature of said gases, but this condensation does not take place so rapidly as to dilute the acid product to any greater extent than in ordinary chamber practice, because of the very rapid formation of sulfuric acid,thus overcoming an objection which applies to apparatus in which water cooled pipes are introduced for the purpose ofquickly"reducin-g the temperature of the gases.

The towers alone may be employed, if desired, although I prefer to combine them with the large lead chambers -6 for the completion of the process, as said lead chambers are sufliciently effective if the temperature of the gases supplied thereto is not abnormally high.

The intimate admixture of the gases and the rapidity of their flow through the lead chambers is an important feature of my invention, hence I so proportion even the large lead chambers 6, in respect to "the volume of flow, that the rate of flow of the gases therethrough will exceed twelve feet per minute,, this being many times faster than in any previous practice with which I am familiar.

In apparatus which I have constructedi the rate of flow of the gases to each row of lead towers 4 approximates ten thousand cubic feet per minute, thefflow from four rows of towers being concentrated, and passed through a plurality of large lead chambers 6, which are connected in series. These 'large lead chambers are each about fifty feet square and 70 feet high, presenting a crosssectional area of twenty-five hundred square feet, and they receive about forty thousand cubic feet of gas per minute, giving a rate of flow of about sixteen feet'per minute, the rate of flow through the small lead towers 4 being proportionately faster, or about one hundred feet per minute.

Throughout its course the sulfur content of the sulfurous gas is progressively decreasing and there is no adulteration of rich gas by admixture with spent or partly spent gas, as in apparatus in which the gas is withrawn from one chamber of a series and introduced into a preceding chamber, The gases escaping from the final chamber 6 of the series are treated, as in the ordinary practice.

I claim:

1. In sulfuric acid apparatus, the combination of a sulfurous gas generator, a Glover tower which receives said gas, and a plu rality of lead chambers receiving the discharge from said Glover tower, said lead chambers being disposed as vertical towers and connected in series alternately at top and bottom and presenting a surface areaequaling or exceeding three-tenths of a square foot for each cubic foot of chamber space.

2. In sulfuric acid apparatus,tlie combination of a sulfurous gasygenerator, a Glover tower receiving the "gas therefrom, a plurality of lead chambers disposed as vertical towers and receiving the discharge from said Glover tower, said lead chambers being connected in series alternatel at top and bottom and presenting a sur ace area equaling or exceeding three-tenths of a square foot for each cubic foot of chamber space, and lead chambers into which the last of said vertical towers discharges, said latter lead chambers each presenting a=much less area of surface for each cubic foot of capacity .than said towers.

In testimony whereof, I have signed my name to thls specification, 1n the presence of two subscribing witnesses.

UTLEY WEDGE. W itnesses HAMILTON D. TURNER, KATE A. BEADLE. 

